Ramires breaks away again for Brazil against the United States. Photograph: Halden Krog/EPA

Brazil's first-half performance in their 3-0 victory over Italy in the Confederations Cup on Sunday confirmed what the results of the last couple of months had been hinting at: for all the doubts about Dunga's supposed pragmatism, all the quibbles over personnel, they will be serious contenders next summer.

The 1-1 draw in Ecuador in March may have been fortuitous, and the defending shambolic, but Argentina's 6-1 defeat to Bolivia a few days later showing the effect altitude can make. Since then, they have put three past Peru and four past Uruguay, before winning 2-1 against Paraguay, their closest challengers in Conmebol qualifying. So now that qualification is all but assured, the big debate is less over Dunga's future, than over what system his side plays: when is a 4-2-3-1 not a 4-2-3-1?

Diamond geezers

At this Confederations Cup, most European observers have happily jotted down their formation as 4-2-3-1, with Luís Fabiano as the centre-forward, Robinho to the left, Kaká as the central creator and Ramires on the right of the attacking three. Gilberto Silva sits in front of the back four, with Fiorentina's Felipe Melo in the slightly more advanced holding role. Yet the Brazilians persist in describing the system as a diamond.

As they see it, Gilberto is the base, with Ramires right and Melo left as carrileros (the shuttlers on the sides of the diamond), Kaká as the playmaking tip, and Robinho as a second striker. At first, that sounds nonsensical, because that isn't how it looks on the pitch, but there is greater subtlety to the Brazilian notation. Gilberto, as the most defensive, they describe as a "first function" midfielder, Melo is "second function" and Ramires, as the most attacking of those three, is "third function".

There is an acceptance too that Robinho pulls left. He does not operate centrally, for were he to do so, he would be competing for space with Kaká and Luís Fabiano. Strangely, he has seemingly reinvented the left-sided attacking position as practised by, for instance, Gianni Riva, in il giocco all'Italiana, the slightly more attacking version of catenaccio practised by Italy in the 1970s. he was, in effect, a converted, tucked-in winger from a 4-3-3, encouraged to move inside by the surges forward of the left-back, who had, since the days of Giacinto Facchetti, been the more attacking of the full-backs in the Italian system.

And once you start to see that, you realise that Ramires, who has had an excellent tournament pounding up and down the right flank, offering deftness as well as energy, could be seen as a modern version of a tornante (literally, a "returner") who, like Jair in Helenio Herrera's Internazionale, is a winger who tracks back. Apart from the fact that the back four is flat rather than employing a sweeper, a middle-aged Italian could easily see this Brazil as an incarnation of il giocco all'Italiana. In that regard, Brazil have become a sort of tactical Rorschach test, with everybody seeing in it what they are culturally disposed to see.

Which begs the question that, if such things are so open to interpretation, whether there is any point putting a name to a formation. There is, because it gives us a basic shape, but we must always be conscious of differences within systems that ostensibly appear to be the same. In fact, one of the great criticisms that can be levelled at the English game historically is that the formation has led the game: players, rather than being treated as individuals whose tactical responsibilities were to be negotiated within a basic framework, were rammed into pre-designated holes.

So while describing the current Brazilian system as a diamond feels almost as antiquated as those British newspapers in the 50s who still listed teams in the 2-3-5 that had died out three decades earlier, so we should be aware that 4-2-3-1 doesn't tell the full story either. And, most intriguingly, the Brazilian 4-2-3-1 differs from the European version precisely because it has evolved via a different route.

Development of Brazil's system

The European 4-2-3-1 derives from 4-4-2. A centre-forward is withdrawn, and the roles of the midfield become more precisely defined, the wide players advancing and the central players retreating, although the wide players still have responsibility for dealing with the attacking intentions of the opposition full-backs.

In Brazil, though, the default for several years has been the 4-2-2-2. It was first showcased to the world in 1982, when Falcao and Cerezo operated as deep-lying playmakers behind Zico and Socrates (the magic square, as it was known). After a flirtation with 3-5-2 under Sebastiao Lazaroni in 1990, the 4-2-2-2 returned in far more defensive form at the 1994 World Cup, at which Dunga, the present coach, operated alongside Marcio Santos at the back of the midfield, with Zinho and Mazinho in front of them as trequartistas, and Bebeto and Romario as the centre-forwards.

The evolution of that system to 4-2-3-1 has come about by pulling one of the centre-forwards back and wider, while one of the trequartistas shuffles a little wider – and in Ramires's case deeper – on the other side to accommodate him. Robinho is thus a forward playing to the left (as Riva did), whereas a European version of the system would have a winger or a midfielder (or a defensive forward) there. So far in this tournament, there has been no sign of him feeling any sense of defensive responsibility.

That may be a problem if he comes up against a right-back of great attacking intent – such as Maicon (who has looked a far more complete player than Dani Alves in the Confederations Cup), but generally the balance looks promising. Ramires, who will join Benfica from Cruzeiro before the start of next season, chugs up and down the right, allowing Melo, the more advanced of the two holders, to focus his attentions more to the left while Gilberto remains central.

It is an adventurous system – counter-intuitively, given Dunga's reputation – but its great advantage is the position of Robinho. As a withdrawn, left-sided central forward, he naturally falls under the marking remit of any member of the opposition. Given one holding midfielder is trying to deal with Kaká, if the other shifts across to stop Robinho, he risks leaving the right-side exposed for Maicon and Ramires. But neither is Robinho playing tight against the opposing full-back or centre-back; in a game that seems increasingly crowded, his has discovered (or rediscovered) a new niche of opportunity.

The ultimate question for European teams

Attacking from wide, of course, is very much in vogue. "When forwards attack from wide to inside, they are far more dangerous," Sir Alex Ferguson explained. "It's funny when I see centre-forwards starting off in the middle against their markers and then going away from goal. Strikers going inside are far more dangerous, I think. When [Thierry] Henry played as a striker, and sometimes when Wayne [Rooney] does, they try to escape and create space by drifting from the centre to wide positions, when that actually makes them less dangerous."

It is all the more dangerous if the wide attacker in operating in conjunction with an attacking full-back: Lionel Messi cutting infield as Alves surges by him is perhaps the most obvious example, but Andrei Arshavin, backed up by either Aleksandr Anyukov or Yuri Zhirkov, has benefited similarly for Russia, while one of Croatia's great strengths – at least until Fabio Capello exposed it by deploying the pace of Theo Walcott high on the right in Zagreb – was Danijel Pranjic's link-up with Ivan Rakitic on the left flank.

It would be a brave manager who called Robinho's bluff and encouraged his right-back to ignore him and surge forward, but that might be the best way to deal with his role. Or a team could play as Chelsea did in Barcelona, with three very deep central midfielders. Or play with a tucked in and purely defensive right-back. And that perhaps is the greatest strength of Dunga's side – that their interpretation of 4-2-3-1 raises questions European sides are not used to answering.